338 A. J. GoUfarb 



zontally on the bottom of the dish. The rate of development was 

 practically the same in the three groups. 



TABLE 15 



Polyps regenerated in 3 days . Regenerated in 6 days 



on Oral Lateral Aboral Total Oral Lateral Aboral Total 



Erect Stems 50% 54% 45% 53% 50% 86% 80% 83% 



Inverted Stems 35% 43% 60% 44% 35% 75% 115% 75% 



Control Stems 33% 37% 44% 37% 33% 48% 66% 48% 



(In Contact) 



No. of branches used 574 



An analysis of these figures gives some interesting details. In 

 the first place, erect stems regenerate a greater total of polyps than 

 the corresponding inverted stems. Secondly, erect stems produce 

 a greater number of oral and a greater number of lateral polyps 

 than do the inverted stems. The lateral branches of inverted 

 stems that bear polyps bend upward toward the basal end of the 

 stem, and these branches are invariably longer than on the erect 

 stems. Thirdly, by far the greatest number of basal polyps are 

 produced on inverted stems, from which they grow upward, and 

 directly opposite to the rest of the stem. If the basal branch of 

 erect stems are long they too bend upward. No emphasis is laid 

 on the control stems in this experiment, as they were influenced 

 by contact with the dish, a disturbing factor at the time not fully 

 appreciated. 



Experiment 14.. Fine sand thoroughly cleaned was put in a 

 dish of water. Erect and inverted stems were embedded in the 

 sand to varying depths. The controls rested horizontally on the 

 sand. The diagrams in the table show the position of the stems; 

 the horizontal lines represent the level of the sand, the parts below 

 it represent the parts embedded in sand, the parts above the line, 

 surrounded by water. 



The conclusions from the previous experiment were more than 

 corroborated. Regeneration on inverted lateral branches is 

 largely inhibited. This is strikingly illustrated, on comparison 

 of columns 2 and 4 and more particularly columns 3 and 5, in 

 which the same number of lateral branches are free, but erect in the 

 one series, inverted in the other. The erect stems of series 4 



